Electronic current regulator



May 21, 1935 c. STANSBURY 2,002,231

ELECTRONIC CURRENT REGULATOR Filed May 24, 1930 BMW/Mu (9mm $3 WM H- (Wmwgx Patented May 21, 1935 UNITED! STATES PATENT OFFICE Cutler-Hammer, Inc., poration of Delaware Milwaukee, Wis., a. cor- Application May 24, 1930, Serial No. 455,444

15 Claims.

This invention relates to a method of and means for controlling the currentfiow through electron discharge devices.

An object of the invention is to provide for controlling the effective current supplied to a translating device through an electron tube.

Another object is to provide for control of the moment of starting the current flow through an electron tube after the application of voltage thereto.

Another object is to provide a controller responsive to variation of a control voltage.

Other objects and advantages will hereinafter appear.

As is well known, the current flow in a high vacuum electron tube provided with agrid varies with the potential of the grid with respect to the cathode. It is thus possible to vary the effective current flow by varying the grid potential. If such a tube is supplied with an alternating potential between the cathode and anode, current can only flow during the positive or working half cycle, that is when the anode is positive with respect to the cathode, and then only if the grid potential is of such a value as to permit any current flow at all. Hence by controlling the instantaneous grid potential during the working half cycles the instantaneous current flow may be controlled in such a manner as to modify the current similarly during successive working half-cycles, or to modify the current differently during successive'half cycles or even suppress certain working half cycles entirely.

It is also known that a gaseous electron tube, such 'for instance as a thermionic tube containing a gas, permits current flow only when the anode is positive with respect to the cathode. If

such a tube is supplied with voltage from an alternating source, current flows only during the working half cycle. If the tube is provided with a control-electrode or grid, the current can only start to flow if the grid potentialwith respect to the cathode has a positive value or at least a lesser negative value than the so called critical grid voltage. This latter is the potential which, when applied to the grid, will prevent the starting of current flow between cathode and anode. By regulating the grid potential it is thus possible to delay the start of current flow at will, and in one aspect the present invention is directed towards this end.

The accompanyingdrawing illustrates by way of example two systems for carrying out the invention, but it will be understood'by those skilled in the art that the invention is capable of-other modifications, all within the scope of these specifications and the appended claims.

In the drawing Fig. 1 shows an embodiment of the invention wherein the energy for controlling the grid is supplied from a line through a transformer, while Fig. 2 shows a modification of the system illustrated in Fig. 1 wherein the transformer has been omitted.

Referring to the drawing, L and L are the terminals of the alternating current supply line. i is a gaseous thermionic tube having a cathode 2, an anode 3 and a grid 4. Connected in series with the tube is a translating device 5, the effective current of which is to be regulated in accordance with the invention. An adjustable condenser ES, having plates 6 and. 6 and paralleled -by an adjustable impedance 7, is connected between the grid 4 and line L A second thermionic tube or rectifier having a heated cathode 9 and an anode I9, is connected in series'with the secondary winding l2 of a transformer I I between the line L andthe grid 3. The adjustable primary winding i3 of the transformer l i may be connected to the lines L and L or any other alternating source, which in the present illustration is assumed to be like frequency, but which may have a difierent frequency from that of the lines L} and L The apparatus operates in the following manner:

When an alternating voltage is applied to the terminals L and L the cathode 2 becomes alternately negative and positive with respect to the anode 3. If'the grid 4 has no voltage impressed upon it, current will flow during the. alternate half cycles, when the cathode 2 is negative.

A voltage is also impressed upon the primary winding,l3 of the transformer H and the resulting current induces a corresponding voltage in the secondary winding l2. The connections of the transformer secondary'winding are such, that the terminal, which is connected to the grid 1, is negative during a half cycle wherein the anode 3 is negative and a corresponding negative charge is accumulated on the plate 6 of the condenser 6. During the next half cycIe the polarities on the electrodes of the tube 1 and on the transformer are reversed, and the tube is rendered conducting, if the negative potential on the grid 4 is not too high. However, as the impedance of the tube 8 is asymmetrical with respect to the current flow, the negative charge accumulated on the condenser plate G can only leak oflf through the impedance I, as no current can pass through the denser 6 is discharged and thus adjust the moment during a working half cycle when the negative potential of'the grid 4 has been sufficiently reduced to permit the tube I to conduct current to the translating device 5. By adjusting the condenser 6, itis furthermore possible to adjust the amount of charge, which the condenser accumulates during the charging period, and this furnishes a second adjustment for the moment when the tube I becomes conducting during a working half cycle.

Thus the amount of energy which is passed during the working half cycles may be regulated and hence the efiective value ofthe current which passes during a series of cycles.

I Also the operation of the controller may be regulated by varying the secondary voltage of transformer II, as for instance by adjustment of .the number of turns thereof. 7

It will be obvious to one skilled in the art, that the transformer I I may be replaced by any other formof impedance, such as a condenser, without altering the principle of operation of the invention. Also the tube 8 may be replaced by any other type of rectifier.

If the tube I is a pure electron tube, the grid will control the instantaneous value of the current therethrough during any moment of a working half cycle, the grid voltage varying from a relatively high to a lower negative value and thus gradually reducing the impedance of the tube in. accordance with the discharge of the storage circuit as aforedescribed.

It is also possible to supply direct current to .the lines L and L and in this case, by using a high vacuum tube, and supplying a pulsating current to the winding I3, the current flow through the tube may be modified or transformed into a pulsating flow, as will be easily understood from the above description.

The elements of tubes I and 8 may, of course,

'be arranged in a single vacuum vessel, whereby.

the electrodes which have similar function may be combined.

Furthermore, it is possible to induce a voltage in the transformer II by a'transient current and thus'control-the current flow in the tube I in response to such transient current.

nals of the alternating current line. 2I is a gaseous thermionic tube having'a' cathode 22, an anode 23 and a grid 24. Connectedin series with the tube is a translating device '25, the effectice current of which is to be regulated in accordance with the invention. An adjustable condenser 26, having plates of opposite polarity 26 and 26 and paralleled by. an adjustable impedance 21, is connected between the grid and the line L. A second thermionic tube or rectifier 28, having a heated cathode 29 and an anode 30, is connected between the grid 24 and Referring to Fig. 2, L and L are the termitube 2I becomes conducting, if not prevented by the negative potential on the grid 24. This negative potential cannot discharge through the rectifler 28, as the rectifier does not pass a negative current from the plate 38 to the cathode 29. It can only 'discharge through the resistance 21 to the plate 26 By adjustment of the impedance 21, it'is possible to adjust the speed withwhich condenser. 26 discharges and thus the moment during the working half cycle, when the negative 2 potential of the grid 24 has been suiiiciently reduced to permit tube 2I to conduct current through the translating device 25 may be adjusted. b

The time of discharge may also be adjusted by adjusting the capacity of the condenser 26.

It is obvious that the tube 2I which has been described as a gaseous thermionic tube, may be replaced byany other suitable tube, such for instance as a high vacuum tube or a tube with a cold cathode and the rectifier tube 28 may be replaced by any othersuitable type of rectifier.

What I claim and desire to protect by Letters Patent is the following:

1. The method of regulating the flow of current through an electronic tube subjected to an alternating potential and having a controlling,

electrode which consists in periodically storing the energy of a unidirectional current, effecting and regulating discharge of such energy-to pro- 3. In combination, a current supply, a circuit to be supplied thereby, an electron tube for continuously regulating the eflective current of said circuit and having a control electrode, an asymmetrically conducting energy storage circuit, and

means to impress a voltage upon said storage circuit and to subject said control electrode to a regulable transient voltage resulting from the discharge of said storage circuit.

4. In combination, a. ,current supply, a circuit to be supplied thereby, an electron tube' for continuously regulating the effective current of said circuit and having a control electrode, an energy storage circuit containing a rectifier, and means to impress a voltageupon said energy storage circuit and to subject said control electrode to a regulable transient voltage resulting from the discharge of said storage circuit.

5; In combination, an alternating current supply, a circuit to be supplied thereby, an electron tube for regulating the efiective current of said circuit and having a control electrode, an asymmetrically conducting energy storage circuit, and means to impress a voltage derived from said supply upon said storage circuit and to subject said control electrode to a regulable transient voltage resulting from the discharge of said storage circuit during alternate half cycles.

6. In combination, an alternating current supply, a circuit to be supplied thereby, an electron tube for regulating the effective current of said circuit and having a control electrode, an energy storage circuit containing a rectifier, and means to impress a voltage derived from said supply upon said storage circuit and to subject said control electrode to a regulable transient voltage resulting from the discharge of said storage circuit during alternate half cycles.

7. In combination, an alternating current supply, a circuit supplied thereby, an electron tube continuously regulating the effective current of said circuit and having a control electrode, and a regulable asymmetrically conducting energy storage circuit connected to said supply and to said control electrode.

8. In combination, an alternating current supply, a circuit to be supplied thereby, an electron tube continuously regulating the effective current of said circuit and having a control electrode, a regulable asymmetrically conducting energy storage circuit connected to said control electrode and means to supply a charging current to said storage circuit during alternate half cycles of the alternating current.

9. In combination, an alternating current supply, a circuit to be supplied thereby, an electron' tube regulating the eifective current of said circuit and havinga control electrode, an asymmetrically conducting energy storage circuit and means to supply a charging current to said storage circuit during alternate half cycles of the alternating current and to impress a regulable transient discharge voltage of said storage circuit upon said control electrode during the other half cycles.

10. In combination, an alternating current supply, a circuit to be supplied thereby, an electron tube regulating the efiective current of said circuit and having a control electrode, an asymmetrically conducting energy storage circuit connected to said supply to receive a. charging current therefrom during alternate half cycles of the supply voltage and a connection between said storage circuit and said control electrode whereby a regulable transient discharge voltage of the former is impressed upon the latter during the other half cycles.

11. In combination, an alternating current supply, a circuit to be supplied thereby, an electron tube for regulating the effective current of said circuit and having a control electrode, an energy storage circuit containing a rectifier, a connection between said supply and said storage circuit to impress upon the latter a potential which is a function of the voltage of the former, and

connections whereby a regulable transient discharge voltage of said storage circuit is impressed upon said control electrode during alternate half cycles.

12. In combination, an alternating current supply, a circuit to be supplied thereby, an electron tube for controlling the effective current of said circuit and having a control electrode, a condenser and a parallel impedance connected between one terminal of said supply and said control electrode, a rectifier connected to said control electrode and means to impress upon said condenser a potential which is a function of the supply voltage and to impress upon said control electrode during alternate half cycles a transient discharge voltage of said condenser.

13. In combination, a current supply, acircuit to be supplied thereby, an electron tube for continuously regulating the effective current of said circuit and having a control electrode, an asymmetrically conducting energy storage circuit, and adjustable means to impress a. voltage upon said storage circuit and to subject said control electrode to a regulable transient voltage resulting from the discharge of said storage circuit.

14. In combination, an alternating current supply, a circuit to be supplied thereby, an electron tube for controlling the effective current of said circuit and having a control electrode, an energy storage circuit containing a rectifier, an adjustable connection between said supply and said storage circuit to impress upon the latter a potential which is a function of the voltage of the former, and connections whereby a transient discharge voltage of said storage circuit is impressed upon said control electrode during alternating half cycles.

15. In combination, an alternating current supply, a circuit to be supplied thereby, an elec-' tron tube for controlling the effective current of said circuit and having a control electrode, a condenser and a parallel impedance connected be tween one. terminal of said supply and said control electrode, a rectifier connected to said control electrode, and adjustable means to impress upon said condenser a potential which is a function of the supply voltage and to impress upon said control electrode during alternating half cycles a transient discharge voltage of said condenser.

CARROLL STANSBURY.

. DISCLAIMER 2,002,28 1.0arroll Stansbury. Wauwatosa, ELECTRONIC CURRENT REGULA- TOR. Patent dated May 21, 1935. Dlsclaimer filed November 6, 1939, by

the assignee, Cutler-Hammer, Inc.

Hereb enters this disclaimer to claims 7 end 8 of said Letters Patent.

[O flicial Gazette December 5 1939.]

DISCLAIMER 2,002,281.O'arroll Stansbm'y. Wauwatosa, Wis. ELECTRONIC CURRENT REGULA- TOR. Patent dated May 21, 1935. Disclaimer filed November 6, 1939, by

the assignee, Cutler-Hammer, Inc. 1 Hereb enters this disclaimer to claims 7 end 8 of said Letters Patent.

[ jfic'ial Gazette December 5. 1939.] 

